Human embryonic stem cells (hESCs) have potential as sources of cells for the treatment for disease and injury (e.g. tissue engineering and reconstruction, diabetes, Parkinson's Disease, leukemia, congestive heart failure, etc.). Features that are important for successful integration of hESC into such therapies include: expansion of hESCs without differentiation (i.e., self-renewal), differentiation of hESCs into a specific cell type or collection of cell types, and functional integration of hESCs or their progeny into existing tissue. Current ex vivo culture systems for hESCs include mouse and human feeder cell layers, media conditioned by feeder cells, or serum-free conditions with complex extracellular matrix proteins. Such systems pose a number of problems, including poorly characterized environmental signals, the transmission of pathogens to hESCs, the transfer of (and “contamination” with) immunogenic epitopes to hESCs leading to rejection after engraftment, poor availability of large-scale supplies of reproducibly high quality purified proteins, and limitations on the ability to scale-up to a clinical process for the treatment of thousands or even millions of patients. In addition, the grafting of hESCs or their differentiated progeny in vivo for tissue repair often suffers from poor cell viability. Therefore, improved platforms are needed for enhancing the survival of implanted cells.
There is a need in the art for improved culture systems and methods for generating stem cells, e.g., hESCs, and/or progeny thereof for clinical use.